Lubrication and Mechanical Properties of Polytetrafluoroethylene Composites Synergistically Reinforced With Silver/Polydopamine/Molybdenum Disulfide Hybrid Fillers

ABSTRACT

Polytetrafluoroethylene (PTFE) is widely used, but is limited in tribology owing to its poor mechanical properties and wear resistance. In this study, silver‐loaded molybdenum disulfide (MoS ₂ ) composites were synthesized via polydopamine (PDA) modification and employed as the reinforcing phase to fabricate Ag/PDA/MoS ₂ ‐PTFE composites. This study focused on the tribological and mechanical properties of these composites. The results indicated that the incorporation of Ag/PDA/MoS ₂ effectively enhanced the tribological performance, thermomechanical properties, and tensile strength of PTFE. Specifically, at a filler content of 1 wt%, the composite exhibited the optimal lubricating performance, with a 42.5% increase in tensile strength. Furthermore, the composites maintained excellent tribological and thermomechanical properties even at elevated temperatures ranging from room temperature (25°C to 250°C). The mechanism for the property enhancement is attributed to the adsorption interactions of Ag/PDA/MoS ₂ , which restrict the movement of the PTFE molecular chains, thereby reinforcing the mechanical strength and wear resistance of the polymer matrix. During friction, Ag/PDA/MoS ₂ underwent adsorption, diffusion, and interlayer sliding. Owing to the adhesive nature of PDA, a protective tribofilm composed of Ag, PDA, and PTFE was formed on the friction surface to achieve a multicomponent synergistic lubrication effect. Thus, these composites exhibit significant potential for oil‐free, self‐lubricating, high‐end engineering applications.